Airplane propeller



1 19, 1932- J. A. CALBY AIRPLANE PROPELLER Filed Sept. 14, 1929 PatentedApr. 19, 1932 PATENT OFFICE JAMES A. CALBY, OF MONTROSE, PENNSYLVANIAAIRPLANE PROPELLER Application filed September 14, 1929. Serial No.392,677.

'This invention relates to propellers for airplanes, and has for one ofits objects to provide a novel and simply constructed propeller of thischaracter which shall embody 5 blades adjustable to permit their anglewith respect to their path of rotation to be varied and which shall havea comparatively long pitch in any adjusted position of the blades.

The invention has for a further object to provide a propeller of thecharacter stated which shall embody means adapted to permit its bladesto be adjusted while it is in motion. a

The invention has for a further objectito provide a propeller of thecharacter stated wherein its disc-area shall be increased as the angleof its blades is reduced and decreased as the angle of its blades isenlarged.

With the foregoing and other objects in,

view, the nature of which will appear as the description proceeds, theinvention consists in the construction, combination and arrangement ofparts hereinafter fully described and claimed, and illustrated in theaccompanying drawings, wherein Figure 1 is a view partly in rearelevation and partly in vertical section of the propeller;

Figure 2 is a top plan view of the propeller, and

Figure 3 is a sectional view taken on the plane indicated by the line 33of Figure 2.

Referring in detail to the drawings, 1 designates the drive shaft of anairplane, 2 and 3 the blades of the propeller and 4 the means throughthe medium of which the angle of the blades with respect to their pathof rotation may be varied.

The blades 2 and 3 are of elongated rectangular formation in contour andare formed integrally with each other. The blades 2 and 3 are made ofelastic material, such as steel or the like, and are provided centrallybetween their end and side edges with an opening 5 for the reception ofthe reduced front end portion 6 of the shaft .1. The blades 2 and3'c0ntact at their center with the shoulder formed by reducing the frontend of the shaft 1, and are secured to the shaft by said shoulder andanut 7 applied to said reduced end. The blades 2 and 3 extend rearwardlyfrom their point of connection with the shaft 1 and are angularlyrelated to their path of rotation, and they are held in this positionagainst the inherent elasticity of the material from which they are madeby a triangular wire stay 8.

The stay 8 is arranged at the rear sides of the blades 2 and 3, and itis connected to diagonally opposite corners of the blades by turnbuckles9. The stay 8 is provided at its center with a hub 10, and it is securedto the hub through the medium of a plate 11, which is fixed to the rearside of the hub and has its ends bent into engagement with the wires ofthe stay, as at 12. g

The means for varying the angle of the blades 2 and 3 with respect totheir path of rotation comprises the strut 8 and sleeve 13. The sleevel3is loosely mounted upon the shaft 1 rearwardly of the blades 2 and 3,and the hub 10is loosely mounted upon the sleeve.

The sleeve 13 is provided at its front end with a hub retaining flange14, and arranged between the hub and flange are antifriction members 15.The sleeve 13 is provided at its rear end with a grooved collar 15forthe reception of the forked end of a lever 17 which when operatedimparts a forward or rearward movement to the sleeve with respect to theshaft 1, and which is adapted to be operated through the medium of anysuitable means, not shown, under the control of the pilot. v

The propeller is held against rotation with respect to the shaft 1 by aspline 1 the turnbuckles 9 are pivotally connected, as at 9?, to

.the stay 8, and are pivotally connected, as at 9 to the blades12 and 3.Any suitable means, not shown, may be employed to secure the turnbuckles9 in adjustedposition. As the stay 8 extends diagonally across the,spect to their path of rotation, and this initial angular position ofthe blades may be increased by moving the sleeve 13 rearwardly on theshaft 1, and the pilot may, while the scribed by said blades, said meansconnecting propeller is in motion, adjust the blades into their maximumangular position or into any position between their normal or minimum ormaximum positions. This may be done by moving the sleeve 13 axially onthe shaft 1. The rearward movement of the sleeve 13 on the shaft 1increases the angular position of the blades 2 and 8, and the forwardmovement of the sleeve on the shaft permits the blades to be moved inthe direction of their normal position by their inherent elasticity;

As the tips of the blades 2 and 3 move inwardly during the adjustment ofthe blades 7 to increase their angular position, the discarea of thepropeller is decreased as the angle of the blades is enlarged, and asthetips of the blades move outwardly while the blades are being adjustedto decrease their angular position, the disc-area of the propeller isincreased as the angle of the blades is reduced.- As the propeller issubjected to edgewise stress only, it possesses great strength even whenof very light construction. As the propeller has a comparatively longpitch, and as the angle of its blades may be varied, it can be rotatedat a comparatively rapid rate with comparatively little power.

While I have described the principle of the invention, together with thestructure which I now consider the preferred embodiment thereof, it isto be understood that the struc ture shown is merely illustrativeand'that such changes 'may be made, when desired, as fall within thescope of the invention as claimed.

I claim 1. A propeller comprising flexible interconnected blades, andmeans connecting jdia-gonally opposed portions of the blades for flexingthe blades to varytheir'angul ar osition with respect to their path ofrotation and coactively vary the diameter of the circle described bysaid blades.

2. A propeller comprising flexible blades of uniform width throughouttheir entire length, a drive shaft for the blades, and meanslongitudinally movable on the drive shaft for flexing the blades to varytheir angular position with respect to their path of rotation, saidmeans connecting diagonally opposed portions of the blades. 7

3. A propeller comprising flexible blades, a stay connected todiagonallyopposite corners of the blades to maintain them in a normalangular position with respect to their path of rotation, a driveshaftfor the blades and meansloosely mounted on thedrive shaft by which thetension of the stay may befvaried to vary the angular position of the'blades and coactively vary the diameter of the circle dediagonallyopposed portions of the blades.

4i. A propeller comprising flexible blades, a drive shaft for theblades, a stay connected to diagonally opposite corners of theb'ladessignature.

to hold them in their normal angular position with respect to their pathof rotation, a hub carried by the stay, and a longitudinally movableadjusting sleeve slidably mounted on the shaft and upon which the hub isrotatably mounted.

5. A propeller comprising flexible blades, a drive shaft for the blades,a stay connected to diagonally opposite corners of the blades to holdthem in their normal angular position with respect to their path ofrotation, a hub carried by the stay, a longitudinally movable adjustingsleeve slidably mounted on the shaft and upon which the hub is rotatablymounted, a flange carried by the sleeve rearwardly of the hub,antifriction elements positioned between the hub and flange, and meansfor longitudinally adjusting the sleeve on the shaft.

6. A propeller comprising blades adjustable to permit their angularposition with respect to their path of rotation to be varied anddecreasing the disc-area of the propeller as their angular position isenlarged and increasing the disc-area as their angular position isreduced, a drive shaft for the blades and means slidably mounted on theshaft for adjusting the blades and securing them in adjusted position,said means connecting diagonally opposed portions of the blades.

7. .A propeller comprising an elongated rectangular sheet of elasticmetal, a drive shaft connected to said sheet, means connected todiagonally opposite corners of the sheet and adapted to bow the sheetand hold the ends of the sheet in an angular position with respect tothe path of rotation of the propeller.

' 8 A propeller comprising an elongated rectangular sheet of elasticmetal, and adjustable means connected to diagonally opposite cornersof'the sheet and adapted to hold the ends of the sheet in an angularposition with respect to the path of rotation of the propeller.

In testimony whereof I hereunto afix my JAMES A. CALBY.

